Pre-heat oven to 400°.
Toss cauliflower florets with 1 Tbsp olive oil and roast in the oven till golden brown. About 15 minutes.
While cauliflower is roasting, toast coriander seeds in a large dry pot (do not use oil or spray) over medium heat until dark brown. 3 minutes. Grind seeds to a coarse powder with mortar and pestle and set aside. (If you don't have a mortar and pestle you can crush the seeds on a cutting board with a heavy stock pot or cast iron skillet)
In the same pot that you toasted the coriander, heat 2 Tbsp olive oil. Stir in chopped onion and cook until fragrant and translucent, stirring occasionally for about 8 minutes. Add garlic and cook 1 more minute.
Add 5 cups water to the pot. Then add carrots, crushed coriander and salt. Stir in the miso paste. Simmer and cook, uncovered, 10 minutes. Stir in roasted cauliflower and cook for another 5 minutes until carrots are tender.
Remove the soup from the heat. Pour soup into a blender, (you may need to do this in batches so you don't overfill your blender.) Purée until smooth.
Pour pureed soup back into the pot and add Parmesan cheese wedge/rind, paprika, onion powder and cayenne. Simmer for about 6 minutes until all the flavors have mingled nicely.
Ladle into bowls and serve topped with a dollop of Greek yogurt, paprika and cilantro leaves.